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YZ250F supermoto gearing?

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I'm switching my '01 YZ250F to supermoto(i'll be running 17" wheels). Is there anyone out there who knows the approximate gearing to run on this bike for supermoto?

I have both 13 and 14 front sprockets and a 44, 46, 48 and a 50 for rears.

I've read the 450s generally run 14/45 or close to it so i was thinking maybe 13/45 for the 250? I'm just trying to start in about the right place to save too much sprocket switching/chain cutting. Any educated guesses/discussion would be appreciated!

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Start by leaving the stock countershaft sprocket and drop the rear 2-3 teeth—fast tracks you may have to go more. 250s are more subject to gearing so if you plan to race, have a larger counter and three different size rears on hand.

SMR

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I made the mistake on my CRF250 of dropping to many teeth on the rear sprocket, I went to 13/47 first and I was getting smoked out of the turns. The stock gearing was is 13/50, it ran great with 17's with 13/49, our local track is pretty tight. :cry:

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It all depends on the track. If you've got the stock transmission, I think its more of a question of the top speed that you'll need on the straights to stay competitive, especially if you're in a class with sportbikes. once you get your local track dialed in, you'll know what gear you'll want to be in for a given corner, and make minor sprocket changes to allow you to be at about 1/2 way through your rpm range in a specific gear so that when you're past the apex and rolling on the gas you get a good drive before having to upshift.

if you're on the street its a different story, its all about rideability.

sprocket selection is critical with the tight ratio transmissions in dirt bikes, and you may as well start building up an assortment of sprockets. I'm running 14/39 on my crf450 on the street (i like this gearing), and i'll probably have to run 15/39 when i put it on the track this summer. you just have to keep an eye on how fast your chain sliders wear out though. i have to slip the clutch up to about 22km/h on any launches from stops, and my bike tops out at an indicated 145 km/h. there's a wide ratio tranny from baja designs that i've been considering for the crf that changes 3rd, 4th and 5th gears that would allow me to run a larger rear sprocket. this would cut down on chain wear, give me more pull out of the corners (since i can use a larger rear sprocket), and allow me to hit a higher top speed.

you need a gear ratio calculator to figure out what you'd like to theoretically hit. there's some on the internet, i just don't remember where.

use some master links; no chain chopping, and they're just as strong. it just takes a couple seconds to safety wire the clip, and you're gone. if i remember correctly, you can safely, without worry, use a master clip-style link on a motor up to ~100HP.

good luck

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